Control Systems
Engineering Creative Solutions
for Fluid Systems Since 1901
Henry Pratt Company | 1
401 South Highland Avenue
Aurora, Illinois 60506-5563
www.henrypratt.com
phone: 630.844.4000
fax: 630.844.4160
Table of Contents
Control Systems
Check-Mate
Details of Operation.........................................................................................................................................................................................1
Equipment Furnished......................................................................................................................................................................................2
Suggested Specification................................................................................................................................................................................2
Low Pressure Oil Accumulator
Design Features.................................................................................................................................................................................................3
Suggested Specification................................................................................................................................................................................4
High Pressure Oil Accumulator
Design Features.................................................................................................................................................................................................5
Suggested Specification................................................................................................................................................................................5
Water Bladder Accumulator
Design Features.................................................................................................................................................................................................6
Suggested Specification................................................................................................................................................................................6
Electro-Check
Interface Systems..............................................................................................................................................................................................7
Diagnostic Electro-Check...................................................................................................................................................................8
Interface Systems......................................................................................................................................................................................9
2 | Henry Pratt Company
PRATT PUMP CHECK SYSTEM PREVENTS THESE OPERATIONAL PROBLEMS
MOTOR
MOTOR
PUMP
FLOW REVERSES WHEN
PUMP STOPS
HYDRAULIC SURGE
OCCURS WHEN VALVE
CLOSURE IS TOO RAPID
Check Mate Details of Operation
Normal Pump Start
In this mode, the pump motor circuit is energized, thereby starting
the pump. As the pump comes up to speed, or design head, three
basic methods are used to signal the Pratt pump check valve.
Single Pressure Switch – The pressure switch is tapped off the
upstream side of the pump check valve. When the discharge
pressure of the pump reaches a level greater than the
downstream system head, the pressure switch trips, energizing
the solenoid circuit to the four-way valve, opening the pump
check valve. During pump start, the two-way solenoid valves are
continuously energized when the pump is on line.
Time Delay Relay – This electrical device is part of the pump
motor circuit. When the pump motor circuit is energized, the time
delay relay is energized, preset to energize the four-way valve
circuit, causing the Pratt pump check valve to open. The amount
of time delay is related to the type of pump and the time it takes
for the pump to come up to speed.
Differential Pressure Switch – This pressure switch is tapped off
the downstream and upstream sides of the Pratt pump check
valve. When the pump/motor circuit is energized, the differential
pressure switch senses when the pump discharge pressure is
greater than the downstream pressure, trips, closing the four-way
valve circuit and causing the Pratt pump check valve to open.
Normal Pump Stop
This mode of operation is selected when the pump is taken off
line for reasons of demand, maintenance, etc. For normal close,
the four-way valve circuit is de-energized, causing the Pratt pump
check valve to close. (The two-way solenoid emergency bypass
valves remain energized during normal pump stop). While the
Pratt pump check valve moves toward the closed position, the
pump/motor set continues to run. The pump/motor circuit is
tripped off by a limit switch on the Pratt pump check valve. The
point at which the limit switch trips out the pump/motor circuit
relates to concerns of hydraulic surge in the system, pump speed,
etc. For some installations the pump/motor circuit is tripped
out prior to the Pratt pump check valve reaching the full closed
position. On some systems, the Pratt pump check valve is fully
closed prior to tripping out the pump/motor circuit. The settings
of the limit switch which trips out the pump/motor circuit are
normally made in the field.
When the pump/motor circuit is tripped out, the two-way solenoid
emergency bypass circuit can be de-energized.
Emergency Closure
This mode of operation usually occurs when an electric power
failure causes the pump/motor set to stop. In an incident of this
nature, the Pratt pump check valve must close at a rate more
rapid than normal closure rates. The need for rapid closure of
the Pratt pump check valve is to prevent a high reverse flow rate
which can backspin the pump and cause damage to the pump/
motor set and drain the system stored water.
On total electric power failure, the four-way valve and the two-way
bypass emergency valves are de-energized. The bypass piping
circuit parallels the four-way valve circuit and provides a larger
cylinder supply flow rate to the Pratt pump check valve cylinder
operator, resulting in rapid closure. If the pump check valve
has the feature of emergency closure, it is recommended that
the pumping system piping should include surge relief devices
because the emergency rapid closure of any pump check valve
will result in hydraulic surge.
Control Function
Normal Pump Start
A. Turn selector switch to “On” position
B. Press pump start button, starting pump motor
C. When pump comes up to desired head, the pressure switch
closes, energizing the four-way valve circuit causing the Pratt
pump check valve to open.
Normal Pump Stop
A. Turn selector switch to “Off” position. This de-energizes fourway valve circuit causing the Pratt pump check valve to close.
B. When the Pratt pump check valve reaches 75% to 95% close,
the momentary limit switch trips, de-energizing the pump/
motor circuit and shutting down the total system.
Emergency Closure
All circuits are de-energized simultaneously, allowing rapid
closure through the two-way valve bypass piping.
On pump check service, valve starts to open only after pump
has reached desired speed (or pressure). When fully open, ball
provides full circular waterway with no more pressure drop than
an equivalent length of pipe. If power loss to pump occurs, valve
closes at desired speed to prevent reversal of flow toward pump.
Upon complete closure, valve is bubble-tight against back flow
towards the pump.
Henry Pratt Company | 1
Equipment Furnished
3A
CLOSE
4A
CYLINDER ROD
IF OPERATOR IS
PUSH TO CLOSE
6
A
SUPPLY
5
2A
4A
NPT TO
CYLINDER
PORT “A”
BY CUSTOMER
NPT
SUPPLY
3A
B
1
2A
2B
1
EXHAUST
FLOW DIAGRAM
CONTROL
FLOW
4B
4B
2B
3B
SELECTOR SWITCH
PI
OFF
ON
LI
1
MS
2
3
4
5
6
TERMINAL
BLOCK
L2
1
NPT EXHAUST
3B
NPT TO CYLINDER
PORT “B”
BY CUSTOMER
1—Two-Position Single Solenoid 4-Way
Valve with Manual Override
2A & 2B —Adjustable Flow Control (Normal Operation)
3A & 3B —Balance and Stop Valve (Emergency Flow
Control & Shut-Off)
4A & 4B —Single Solenoid 2-Way Valve (Normally Open)
5 — NEMA 4 Terminal Box with Terminal Block
6 —NEMA 12 Single Door Control Cabinet
1
CI
4A
PS
4B
4B
CONTROL VOLTAGE
4A
1 — 4 Way Valve
Solenoid Coil
4A — Emergency
4B 2-Way Valve
Solenoid Coils
C1 — Motor Starter Holding Contact
P1 — Pump Start Button
MS — Motor Starter Solenoid
MLS — Momentary Limit Switch
1 — 4-Way Valve Solenoid Coil (By Pratt)
PS — Pressure Switch Contacts
4A & 4B — Emergency 2-Way Valve Solenoid Coils (By Pratt)
WIRING DIAGRAM
Suggested Specifications
The control system for the pump check valve shall provide
the following functions:
1. Independent adjustable rates of valve opening and
closing operations.
2. Independent adjustable emergency closure rate
resulting from an electric power failure or other
operational signal eliminating power to the system.
The system shall be provided with a single solenoid fourway valve for the normal open and close function. Two
solenoid operated two-way valves shall be provided for
emergency closure, bypassing the single solenoid fourway valve. Separate adjustable speed control valves shall
be furnished for open, close and emergency operation.
The system shall be provided with a manual override for
the normal open and close function.
The required speeds of operation shall be as follows:
Normal open – 6
0 seconds minimum
300 seconds maximum
2 | Henry Pratt Company
Normal close – 6
0 seconds minimum
300 seconds maximum
Emergency Close – 1
0 seconds minimum
20 seconds maximum
The control system shall be fully piped and wired, and
contained within a NEMA 12 cabinet with a hinged access
door. Electrical wiring shall terminate in a separate NEMA 4
junction box within the control cabinet.
The pump check valve should be furnished with three limit
switches. One each for the full open or full close positions,
and the third switch shall provide momentary interruption
of the pump motor control to initiate pump shutdown prior
to 100% valve closure to minimize hydraulic surge.
The pump check system shall be the Check-Mate system
as manufactured by the Henry Pratt Company.
Low Pressure Oil Accumulator System
Design Features
• Custom sized to match application
• Fully automatic system
• Between 10 and 500 gallons of usable oil delivered
even with loss of electrical power
• System supply isolation valve provided for additional
plant safety
• Sight gage with integral checks that automatically close
with accidental breakage of gauge glass
• Low oil level switch in sump tank locks out pumps
• NEMA 12 electrical control cabinet (NEMA 4 shown)
• Air filter to remove excess moisture for air lines
• 200 mesh suction filters on each oil pump
The low pressure accumulator system consists of a
cylindrical pressure tank, oil sump tank, NEMA cabinet, one
(1) air compressor, two (2) motor driven oil pumps and all
necessary controls and accessories mounted and piped on
a fabricated steel base with lifting eyes.
Pressure Tank – 100 to 1,000 gallons in size
The tank provides oil pressure between 80 psig minimum
and 150 psig maximum with 150 psig air pressure above
the oil. The tank is sized to stroke the hydraulic cylinders
three (3) times between these pressures without electric
power. Under normal operation with electric power, the
controls start the oil pump when the pressure drops to
145 psig and stops the pumps when the proper oil level
is reached. The pressure tank is constructed and tested
in accordance with the latest ASME Code for Unfired
Pressure Vessels and code stamped. Standard features
include a relief valve, gauge glass with ball check gauge
cocks, float switch and cleanout hole.
Oil Pumps/Air Compressor Units –
For proper fluid control
The two positive displacement oil pumps wired in a lead/
lag circuit maintain the correct oil level in the tank. They
are sized to pump the usable oil volume in less than 10
minutes, 5 gpm minimum. Standard features are relief
and isolation valves, a common outlet filter and controls
necessary to maintain proper air pressure in the tank.
A single stage air compressor unit provides air under
pressure to maintain the oil at 150 psig. The units recharge
the pressure tank in less than 20 minutes, 3/4 scfm
minimum. The unit is totally enclosed with a metal guard
for safety. The compressor is equipped with relief valve,
isolation valve, outlet filter and controls necessary to
maintain proper air pressure
in the tank.
If oil pump fails to perform its function or if the system
demand is high, the lag pump will start. An alternator is
provided so that, upon each charging cycle, a different
pump will be started to equalize service loads.
Electrical controls – Fully automatic
All of the controls, pressure switches, alternator and motor
starters are mounted in a NEMA 12 enclosure with heavy
duty oil tight panel lights, buttons and switches, for easy
access and adjustment. The pressure gauge is mounted in
the cabinet floor for high visibility. The controls make the
system fully automatic and contain safety alarm circuits
for low oil level or low pressure conditions to protect the
equipment.
Oil Sump Tank – With low level lock-out switch
The oil return sump tank of welded steel plate receives
the working capacity of oil stored in the pressure tank. The
reservoir is fitted with a gauge glass, a low level oil cut-off
float switch, a drain connection and a screened fill cap.
Henry Pratt Company | 3
Low Pressure Oil Accumulator System Suggested Specification
General
An oil accumulator system shall be furnished to supply oil
under pressure to actuate the hydraulic cylinder operated
valves. The oil accumulator system shall consist of a
vertical cylindrical pressure tank, rectangular oil sump
tank, electrical cabinet, one (1) air compressors, two (2)
motor driven oil pumps, and all necessary controls and
appurtenances mounted and piped on a fabricated steel
base with lifting eyes for floor mounting. The system shall
be designed to use a petroleum base hydraulic oil with
viscosity of 90 SUS at 100ºF.
Pressure Tank
The pressure tank shall be constructed and tested in
accordance with the latest ASME Code for Unfired
Pressure Vessels and code stamped. The tank shall be
sized to stroke the hydraulic cylinders three (3) times
between the pressures of 80 and 150 psig, with no electric
power available. Under normal operation, with electric
power for operating the oil pumps, the controls shall
function to start the oil pumps when the pressure drops to
145 psig and stop the oil pumps when the proper oil level
is reached. The pressure tank shall be equipped with a
relief valve, gauge glass with ball check gauge cocks, float
switch, drain, and a cleanout hole.
Oil Return Reservoir
The oil return reservoir shall be constructed of a welded
steel plate and shall be of ample size to receive the working
capacity of oil stored in the pressure tank. It shall be fitted
with a gauge glass, a low level oil cut off float switch, a
drain connection, and a screened fill cap.
4 | Henry Pratt Company
Air Compressors/Oil Pumps
Two (2) motor-driven air compressors with relief valves,
isolation valves, a common outlet filter, and controls
necessary to maintain proper air pressure in the pressure
tank shall be furnished. The units shall be sized to
recharge the pressure tank in less than 10 minutes, 1-1/2
scfm minimum. Two (2) motor-driven oil pumps with
relief valves, isolation valves, suction filters, and controls
necessary to maintain proper oil level in the pressure tank
shall also be furnished. The oil pumps shall be sized to
pump the usable oil volume in less than 10 minutes, 5 gpm
minimum. The oil pump shall work in an alternating lead/
lag circuit so that, if the unit is unable to build pressure, the
lag unit shall start.
Control Cabinet
A NEMA 12 control cabinet containing a panel interlocked
main circuit breaker, motor circuit breakers, motor circuit
protectors, motor starters, control transformer, alarm reset
buttons, Hand-Off-Auto switches, pilot lights, control relays,
terminal strip, pressure gauge, three pressure switches,
and any additional equipment necessary for proper
operation of the system shall be provided. Motors shall be
suitable for _____ volt, 3 phase, 60 cycle power and of
the open drip proof construction. Lights, alarm contacts,
and reset buttons shall be provided for the low oil level and
low pressure alarm conditions.
Miscellaneous
Interconnected piping between the hydraulic and
pneumatic components shall be tubing or pipe.
The supply and return lines shall be sized to assure
minimum pressure loss at the emergency cylinder flow
rate. The accumulator shall be connected to the hydraulic
cylinders in the manufacturer’s shop, filled to the normal
operating level with oil, and tested to verify correct
mechanical and electrical operation. All exposed carbon
steel surfaces are to be cleaned thoroughly, removing all
rust, scale, dirt, and grease, and painted with an industrial
rust resistant primer and a waterproof industrial enamel. In
preparation for shipment, all openings shall be plugged and
all instrumentation adequately protected.
High Pressure Oil Accumulator System
Design Features
•
•
•
•
•
•
Custom designed
Between 1 and 100 gallons of usable oil after power failure
Isolation valves on each accumulator for easy servicing
System remains operational while an accumulator is serviced
10 micron return line filter to protect components
NEMA 4 electrical cabinet
The high pressure system consists of a bank of nitrogencharged accumulators, a pump/motor set mounted on an
oil sump tank, an electrical motor control cabinet, and all the
necessary controls and accessories.
Accumulator Bank – Precharged cylinders
The bank of accumulators is sized to stroke the hydraulic
cylinders three (3) times between the pressures of 1400
and 1000 psig. Pratt high pressure accumulator systems are
available in all capacities, but always contain a minimum of two
accumulators. A charging and gauging assembly is shipped with
each rack to check pressures.
Oil Pump/Motor Set and Sump Tank –
With integral hydraulic controls
The positive displacement pump/motor set is sized to charge
the accumulator with oil in less than five minutes, 1 gpm
minimum. The open drip-proof motor is suitable for all 3 phase,
60 cycle power. The unit features an integral strainer, relief
valve, gauge and level indicator.
Control Cabinet – Manual and automatic operation
The NEMA 4 (rainproof/outdoor) electrical cabinet houses
the motor starter, Hand-Off-Auto selector switch, start button
and circuit breakers. Using the pressure switch, the unit will
automatically start the oil pump when the pressure is below
1400 psig and stop the oil pump at 2500 psig. The control
cabinet provides extra protection from dust and water, and is
wall mounted.
Suggested Specification
General
A high pressure oil accumulator
system shall be furnished to supply
oil under pressure to actuate the
hydraulic cylinder operated valves.
The oil accumulator system shall
consist of a pump/motor set mounted
on an oil sump tank, an electrical
motor control cabinet, a bank of
accumulators, and all necessary
controls and appurtenances. The
system shall be designed to use a
petroleum base hydraulic oil with a
viscosity of 90 SUS at 100ºF.
Sump Tank
The sump tank shall be constructed of welded steel plate and
shall be of ample size to receive the working capacity of the
oil stored in the accumulators, 10 gallons minimum. It shall be
fitted with a flush type fluid level indicator, a clean out cover,
filler/breather, and a drain connection. In addition, the return
connection shall contain a 10 micron screw canister type fluid
filter with internal bypass.
Pump/Motor Set
The positive displacement pump/motor set shall be sized to
charge the accumulators with oil in less than five minutes, 1
gpm minimum. The motor shall be suitable for all 3 phase, 60
cycle power and of the open drip-proof construction.
Control Cabinet
A NEMA 4 electrical control cabinet shall house a motor
starter, Hand-Off-Auto selector switch, start button, and circuit
breaker. Using the pressure switch, the unit shall function to
automatically start the oil pump when the pressure is below
1400 psig and stop the oil pump at 2500 psig.
Accumulator Bank
The oil pump shall charge a bank of accumulators (quantity
two minimum) sized to stroke the hydraulic cylinders three
(3) times between the pressures of 1400 and 1000 psig. The
accumulators are to be nitrogen pre-charged, and built in
accordance with the ASME Code for Unfired Pressure Vessels.
The accumulators shall be affixed to a metal rack assembly
for floor mounting. Each accumulator shall be fitted with an
isolation ball valve and piped to a common header containing a
system isolation valve and an accumulator drain valve. Supplied
with the assembly shall be a charging gauging assembly.
Miscellaneous
All piping and fittings shall be seamless
steel tubing with a rated working pressure
of 6000 psi. All exposed carbon steel
surfaces are to be cleaned thoroughly,
removing rust, scale, dirt, and grease, and
painted with an industrial enamel. The
pump motor set, electrical cabinet, and
accumulators shall be connected to the
hydraulic cylinders in the manufacturer’s
shop, filled to the normal operating
level with oil, and tested to verify correct
mechanical and electrical operation. In
preparation for shipment, all openings
shall be plugged and all instrumentation
adequately protected.
Henry Pratt Company | 5
Water Bladder Accumulator System
Design Features
•
•
•
•
•
•
•
•
•
•
Custom sized to match application
Between 20 and 500 gallons of usable water supply.
Standard fail-safe operation
Requires only 110 volt power
Fully automatic system
Fully adjustable high/low water pressure
NEMA 12 enclosure standard
Corrosion proof fiberglass epoxy coated accumulators
System design based on standard equipment
Supply pressures up to 200 PSI
The water bladder
accumulator system
consists of a series of
water accumulators
combined with a fully
piped pump and pressure
control system housed
inside a NEMA 12
enclosure. All water
bladder control systems
are skid mounted for
ease of installation.
Simply hook up the
water bladder system to any water supply and 110 volt
service and the system is ready to be piped to any cylinder
operator. The water bladder accumulators are pre-charged
at the factory and suitable for all indoor locations.
6 | Henry Pratt Company
Benefits of the water bladder accumulator
•
•
•
•
•
•
Fully automatic – self starting water pump
3X reserve supply in the event of a power failure
Immediate high volume supply
System recharges quickly for high service applications
Stainless piping and NEMA 4X enclosures available
Gages monitor accumulator pressure and system
pressure
• Fully adjustable accumulator and system pressure
settings
• Legend plates identify all critical components
• Easy replacement of components
Suggested Specification
A water bladder accumulator system shall be furnished
to supply water under pressure to actuate the hydraulic
cylinder operated valves. The water bladder accumulator
system shall consist of skid mounted tanks with a usable
volume to cycle (fully closed to fully open to fully closed)
the cylinder actuators 3 times at a minimum of 60 psig.
The system shall be of a manufacturer who is regularly
engaged in the manufacture of this equipment and shall
be provided complete with interconnecting piping, valves,
control panel and electrical equipment to operate as
a single unit. The system shall be Pratt Water Bladder
Accumulator Series WBA, or equal.
Diagnostic Electro-Check and Standard Electro-Check
Design Features
•
•
•
•
•
•
Ice cube type relays for easy replacement
Solid state timing relays for long life
Flashing alarm lights provide high visibility
Rigid NEMA 4 enclosure with terminal strip
Heavy duty oil tight push buttons and lights for long life
Remote alarm contacts
Control Features
• Normal Pump Start – provides signaling of pump start
and valves opening sequence. Also displays valve open
or closed position and pump status
• Pump Stop – controls and monitors closure of check
valve. Automatically stops pump at 70 – 95% closure
Pump Safety Check Features
Monitors and safely controls valve and pump in the
event of:
1. Loss of all electrical power
2. Pump motor overload
3. Failure of valve to open
4. Line blockage
5. Pump failure
Diagnostic Electro-Check
Monitors and Displays System Operational Status
Only Pratt’s Diagnostic Control unit monitors three system
parameters with three individual timers. Conditions are
sensed by valve travel and pressure switches mounted
on the pump discharge pipe. Therefore, any expected
transient conditions can be filtered out by adjusting the
appropriate timers.
Timer No. 1 is set to allow enough time for the pump to
build pressure and the valve to begin opening. Timer No.
2 is set to the maximum allowable duration for a high
pressure transient. Timer No. 3 is set to the maximum
allowable duration for a low pressure transient. Then if any
timer monitors an alarm condition for a time greater than
its setting, it energizes a lockout relay and one of the three
alarm lights – pump, Hi pressure or Lo pressure alarm. The
cause of the emergency shutdown can be quickly identified
by the three alarm lights.
Electric Pump/Valve Interface Systems
Both systems are designed to work with either the Pratt
Hydraulic Check-Mate or Air/Oil Check Mate units in
controlling the pump and pump discharge ball or butterfly
valve. Control panels provide for valve position and alarm
indication, timed alarm control, and emergency stop
capability. A relay will lock out the pump after an alarm
condition arises, and a reset button must be pressed
before the pump can be restarted. The enclosures are wall
mountable and can be located at the valve or in the pump
control room. Pratt modular control systems offer flexibility
and safety as well.
At the Pratt Control System Center, each unit’s control
sequence is tested with the Pratt Pump System Simulator
which matches the customer’s pump and pressure
switches. The pump check valve must work closely with
the pump controls to function properly. This test procedure
ensures compliance with design specifications and testifies
to Pratt’s professional approach.
Henry Pratt Company | 7
Diagnostic Electro-Check Sequence of Operation
Pump Start
SCHEMATIC WIRING DIAGRAM
1.
2.
3.
4.
Only the valve “Close” light is on.
A maintained pump signal is given at Terminal 3.
CR1 is energized, closing contacts (Lines 4 & 15).
CR1 contact (Line 4) energizes pump motor starter and pump
“Run” light.
5. As pump discharge pressure rises. PS1 (Line 2) closes,
energizing 4SV and opening the pump check valve. During
valve travel, both “Open” and “Close” lights are on.
6. When valve is full open. LSO contact (Line 7) opens and the
“Close” light is de-energized.
7. As the pump runs, the “Run” and “Open” lights are on.
Pump Stop
1.
2.
3.
4.
The pump run signal is removed from Terminal 3.
4 SV is de-energized, starting pump check valve closure.
CR1 is de-energized, opening contacts (Lines 4 &15).
The pump continues to run, powered thru the closed LSC,
MLS and MSH contacts (line 5).
5. When the pump check valve is 70-95% closed, MLS opens
momentarily and de-energizes the pump motor starter. If MLS
is not used, LSC will turn off pump when valve is fully closed.
6. Pump “Run” and valve “Open” lights are de-energized.
Pump Safety Stop
1. Upon loss of all electrical power, the 2SV solenoids (Line
3) are de-energized, closing the pump check valve at the
emergency rate.
2. If the pump motor starter overloads (Line 5) open, 4SV and
2SV are de-energized, closing the pump check valve at the
emergency rate.
3. Line pressure and valve position are continuously monitored
by PS2, PS3, and LSC. If the emergency exists for the
time setting on its timing relay, TR1, TR2, or TR3, then the
corresponding alarm lockout relay and alarm light will be
energized. Pump safety shut down begins by opening one
of the alarm contacts on Line 1 – valve will close and the
MLS (Line 5) will shut down the pump. The pump can not be
re-started until “Reset” (Line 9) is pressed. The pump safety
stop sequence will be initiated
under the following conditions:
a. If the valve fails to begin
opening in the time set on TR1
TERMINAL STRIP
(Line 15).
b. In case of line blockage or
inadvertent valve closure, the
pump discharge pressure
CR1 CR2 CR3 CR4
will rise to the pump shut-off
pressure and close PS2 (Line
TR1 TR2 TR3
16).
INSIDE
8 | Henry Pratt Company
c. In case of line break or parallel pump trip, the pump
discharge pressure will fall below normal pressure and
close PS3 (Line 17).
d. In case of local emergency, the red “Stop” button (Line 8)
can be pressed. The valve will close at the normal rate and
shut off the pump at MLS (Line 5) setting.
e. Remote alarm contacts: CR2, CR3 and CR4 (Line 18), are
provided. (10 amps. Max.)
12-15/16"
10"
14-3/4"
7-3/8"
RUN
OPEN
CLOSE
STOP
PUMP
ALARM
HI PRESS
ALARM
LOW PRESS
ALARM
RESET
15-1/2"
FRONT
5/16" DIA.
CONTROL ENCLOSURE
SIDE
Standard Electro-Check Sequence of Operation
12-15/16"
10"
Pump Start
1.
2.
3.
4.
Only the valve “Close” light is on.
A maintained pump signal is given at Terminal 3
CR1 is energized, closing contact (Line 4).
CR1 contact (Line 4) energizes pump motor starter and pump
“Run” light.
5. As pump discharge pressure rises, PS1 (Line 2) closes,
energizing 4SV and opening the pump check valve. During
valve travel, both “Open” and “Close” lights are on.
6. When valve is full open, LSO contact (Line 7) opens and the
“Close” light is de-energized.
7. As the pump runs, the “Run” and “Open” lights are on.
Pump Stop
1.
2.
3.
4.
The pump run signal is removed from Terminal 3.
4SV is de-energized, starting pump check valve closure.
CR1 is de-energized, opening contact (Line 4).
The pump continues to run, powered thru the closed LSC, MLS
and MSH contacts (Line 5).
5. When the pump check valve is 70-95% closed, MLS opens
momentarily and de-energizes the pump motor starter. If MLS
is not used, LSC will turn off pump when valve is fully closed.
6. Pump “Run” and valve “Open” lights are de-energized.
Pump Safety Stop
1. Upon loss of all electrical power, the 2SV solenoids (Line 3) are
de-energized, closing the pump check valve at the emergency
rate.
2. If the pump motor starter overloads (Line 5) open, 4SV and
2SV are de-energized, closing the pump check valve at the
emergency rate.
3. If the valve fails to begin opening in 10-120 seconds
(adjustable), the time delay relay contact (Line 8) energizes the
alarm lock-out relay CR2. CR2 contact (Line 1) initiates “Pump
Stop” sequence above, and energizes “Emerg. Stop” light.
Pump can not be restarted until “Reset” button is pressed.
4. In case of line blockage or inadvertent valve closure, the pump
discharge pressure will rise to the pump shut-off pressure and
close PS2 (Line 12). PS2 will energize TR initiating the “Pump
Stop” sequence and energizing “Emerg. Stop” light. (PS2 is
optional).
5. In case of line break or parallel pump trip, the pump discharge
pressure will fall below normal pressure and close PS3 (Line
13). PS3 will energize TR initiating the “Pump Stop” sequence
and energizing “Emerg. Stop” light. (PS3 is optional).
6. In case of local emergency, the red “Stop” button (Line 10) can
be pressed. The valve will close at the normal rate and shut off
the pump when MLS setting is reached (Line 5).
7. Remote “Emerg. Stop” alarm contact, CR2 (Line 13) is
provided. (10 amp max.)
RUN
OPEN
CLOSE
STOP
EMERG.
STOP
RESET
TERMINAL STRIP
12-3/4"
13-1/2"
TR1
CR1
CR2
INSIDE
FRONT
5/16" DIA.
CONTROL ENCLOSURE
Suggested Specification
In addition to the pump check valve hydraulic controls, an electric
control panel shall be supplied containing all necessary relays,
timers, buttons and lights to interface the pump controls with the
pump check valve controls. The panel shall provide for:
1. Visual indication of valve position with red and green indicating
lights.
2. Visual indication of alarm conditions with amber flashing light.
3. Emergency shut down of pump and valve by an external
button.
4. Pump system lockout after an alarm condition. System to be
started again only after the reset button is pressed.
The alarm function of the panel shall include an adjustable solid
state timing relay, lockout relay, flashing light and reset button. The
controls shall be housed in a continuous hinge NEMA 4 cabinet
suitable for wall
mounting. Each
SCHEMATIC WIRING DIAGRAM
alarm relay shall
L1
L1
have a set of
CONTROL VOLTAGE 115 VAC
contacts wired
1
3
4
2
to the terminal
strip for remote
5
6
5
indication.
OFF
HAND
AUTO
CR2
CR1
1
RM
4, 11
PSI
2
4SV
2SV
2
3
2SV
CR1
RUN
4
LSC
MLS
OLS
MSH
MS
5
The control
system shall be
the Standard
Electro-Check,
Diagnostic
Electro-Check
system as
manufactured by
the Henry Pratt
Company.
LSC
6
LSO
7
7
6
OPEN
8
R
CLOSE
A
EMERG. STOP (FLASHING)
TR
8
CR2
RESET
CR2
9
STOP
1, 9, 13
10
LSC
11
CR1
TR
9
LSC
12
PS3
13
CR2
10
11
ON DELAY
Dotted Line
Wiring by others
Optional Equipment:
• Pressure switches
• Individual Alarm Pilot Lights for pump failure, low pressure,
and high pressure conditions.
• Cabinet floor stand
• Individual Lockout Timers for monitoring alarm conditions
Henry Pratt Company | 9
PRATT PRODUCT GUIDE
Model
2FII
Monoflange
MKII
Plug
Valve
Triton®
XR70
Indicating Butterfly Valve
UL & FM approved
Tilting Disc
Check Valve
Triton®
XL
N-Stamp Nuclear
Butterfly Valve
Cone
Valve
Rectangular
PIVA Post Indicating Valve Assembly
UL & FM approved
Sleeve
Valve
Rubber Seated
Ball Valve
Triton®
HP250
Check
Valve
Metal Seated
Ball Valve
Control
Systems
Plunger Valve
Henry Pratt Company
Air Valve
10 | Henry Pratt Company
401 South Highland Avenue
Aurora, Illinois 60506-5563 - US
P: 630-844-4000 F: 630-844-4160
www.henrypratt.com
ISO 9001: 2000 Certified
©2014 Henry Pratt Company | Printed in the U.S.A. | CONT-0614